import sys

X = int(input())

if X >= 30:
  print('Yes')
else:
  print('No') import sys sys X = int(input()) X int(input()) int input() input if X >= 30:
  print('Yes')
else:
  print('No') X >= 30 X 30 print('Yes') print 'Yes' print('No') print 'No' X = int(input()) int(input()) X
import sys

X = int(input())

if X >= 30:
  print('Yes')
else:
  print('No')